This invention relates to pressure washers and, in particular, to a pressure washer apparatus that is mobile with an improvement directed to the handling of chemicals.
Methods of cleaning structures have varied greatly over the years. The particular method of cleaning larger structure, such as multi-storied buildings, is often a direct function of the height of the building and its location. One such method is the use of a mobile pressurized water system that can be transported to the building and capable of delivering high pressure water through a flexible hose. The pressurized water loosens the materials and provides a rinse. If the water is fed continuously, the pressure washer allows high speed cleaning on a continuous basis. When a chemical is added to the water, the pressure washer provides a scouring effect capable of cleaning most any surface.
Most conventional pressure washers are not feasible or effectively capable of reaching multi-stored buildings where back pressure causes a loss in operating pressures. One method of addressing this problem is to increase the size and speed of the operating pumps, however, the higher pressures results in control problems and the higher pump pressures can endanger the operator of the system and surrounding personnel. In this manner the concentration of chemicals, as well as the ability to insert and regulate the chemical, becomes a problem. Still another problem with the prior art is storing chemicals and related cleaning materials in a securable enclosure both when the pressure washer is in use and when it is stored.
Mobile pressurized water sprayers are known in the art as disclosed in U.S. Pat. No. 3,227,376 issued to Rittenhouse. The Rittenhouse reference includes a motor enclosed in a dedicated housing but is a spraying device for agricultural applications. As such, Rittenhouse employs jets to force mist into a stream of substantially non-turbulent air. This non-turbulent airflow is created by fan blades that direct ambient air through a specially-vaned, hollow chamber. The fan which creates the necessary airflow is linked to a motor by a pulley system. The Rittenhouse components are not, as a group, enclosed within a housing structure. Instead, they are simply mounted on an open-air trailer platform. This open-air design is critical to the Rittenhouse device: enclosing the Rittenhouse elements would make them inoperable and requires an xe2x80x9copen-ended elongated tubular sleevexe2x80x9d. Creating a housing around the Rittenhouse elements would not only prevent distribution of the mist created by the sprayer jet nozzles, it would interrupt the continuous flow of air needed to distribute the mist correctly.
U.S. Pat. No. 4,821,958 issued to Shaffer discloses a mobile pressure cleaning unit. Shaffer has a selection means which communicates sequentially with additive tanks and a known repeating sequence and with the mixing means for solution makeup. Liquid is drawn from a water source and one of the additive tanks with a main pump unloader, pressure sensitive valve communicating with the main pump output wherein the pressure sensitive valve causes the main pump to reticulate the liquid to the main pump input where the output pressure of the main pump exceeds a known value. A pressure sensing means forms an intrical portion of the unloader valve wherein a pressure change in the output to the main pump causes the selection means to advance to the next position in the sequence. Shaffer application utilizes a pressure switch rather than a flow switch to detect the opening and closing of the applicator""s on/off valve. The applicator is then capable of sequentially cycling a selector valve to a desired additive by opening and closing of the on/off valve. The applicant""s device is not directed to a switching mechanism.
U.S. Pat. No. 3,612,356 issued to McVey discloses a apparatus for spraying turf. The control system on McVey is directed to controlling the rate of flow from five different vented containers. McVey describes each container as containing matter such as turf fertilizer, weed control, fungus control, crabgrass control, and root zone control. The operator sets calibrated dials to a preselected number which in accordance with the amount of liquid chemicals to be applied to a particular lawn. The Applicant""s device is limited to a pressure washing device and the controls provide a level of operator""s safety by keeping an individual outside the confines of a low pressure system. Unlike McVey, the Applicant""s invention operates at high pressure and is capable of delivering pressurized water to items despite their elevation.
U.S. Pat. No. 3,831,849 issued to Studinger discloses a mobile self contained pressure sprayer. Applicant has improved upon the Studinger device by making a mobile self contained pressure with numerous improvements making it safe for not only the operators of the device, but also people in the immediate vicinity. The Studinger skid mounted sprayer is exposed to the elements wherein its chemicals and rotatable pumps can all be accessed by the curious such as children. The Applicant invention is fully enclosed mobile sprayer having a unique chemical injection system.
Thus, what is needed in the art is a mobile pressure washer capable of operating at high pressures with all pumps and chemicals placed within an enclosure that can be made mobile or placed stationary providing for the safety of the operator and surrounding personnel, and for providing continuous pressures despite the incoming water pressures.
Among the several aspects and features of the present invention may be noted the provision of a totally enclosed, and thus securable, mobile pressure spraying apparatus. The teaching of the instant invention allows for an enclosure that is compartmentalized such that it is partitioned into multiple separate portions providing safety to an operator while working within the trailer. The forward most portion houses the engine and pump assembly. The middle region houses the various fluid tanks and the control valves for the cleaning apparatus. The rearward third compartment is for storage of miscellaneous items, such as hoses, tool boxes, and extra spray guns. Running fully lengthwise and widthwise above these three compartments is a rack for housing of the various ladders and lift mechanisms necessary for a typical building cleaning job.
Water pressure is generated by a piston-type positive displacement pump. The engine driving the pump is diesel powered which minimizes fuel related vapor hazards typical of gasoline powered engines. The engine drives the pump through a belt-pulley arrangement positioned on a two-tiered floor secured skid that allows height adjustment. In addition, the pump unit design allows for repair or replacement of the assembly separate from the enclosure.
The pumping system may include a sealed or open low pressure holding tanks allowing a higher volume of incoming water by elimination of back pressure. The holding tank also allows for the return of unused pressurized water to accommodate the positive displacement pump. This eliminates water waste typical of overflow from open tanks.
The system employs gate valve assemblies allowing a variety of pressure controls including the ability to choose between chemical dispensing and high pressure water spraying. Chemical injection system eliminates the need for open storage containers and manually mixing thus eliminated the risk of chemical exposure from mixing in open tanks.
The enclosed mobile pressure sprayer apparatus of the instant invention comprises a mobile trailer having four outer walls a roof and a floor. The walls include at least one-door for access to an internal area of the trailer which is divided into at least two sections, namely a pump section and a storage section. An inlet valve is secured to an outer wall of the trailer and is for coupling to a low pressure water source, a backflow preventer prevents water from returning back into the source. A first selection valve is secured to an outer wall of the trailer and fluidly coupled to an outlet of the backflow preventer. The valve is selectable between the raw water source and a raw chemical source such as concentrated detergent or chlorine. The use of concentrated chemicals eliminate the need for a separate mixing tank.
A second selection valve is also secured to the outer wall of the trailer and fluidly coupled to the water source and raw chemical source and selectable there between. A storage tank is then coupled to an output of the second selection valve providing a mixing chamber before a pressure pump. A high pressure displacement pump is coupled to the storage tank and followed by a another selection valve also secured to an outer wall of the trailer. The valve is selectable between the storage tank and the pump provided both unpressurized as well as pressurized fluid. A regulatory valve is secured to an outer wall of the trailer and y coupled to the third section valve for controlling the pressure of fluid from the pump and providing a selective return of fluid to the storage tank. A conventional sprayer wand controls fluid output.
Thus, an objective of the instant invention is to provide a mobile enclosed pressure sprayer having a unique chemical injection system that allows for chemical injection by use of low pressure chemical injection pumps with all controls mounted external to the enclosed equipment area.
Another objective of the instant invention is to provide a mobile enclosed pressure sprayer having all chemicals, pumps, and related cleaning equipment placed within a lockable enclosure. The pumps are operated with external controls to reduce theft and vandalism while increasing operator safety.
Other objectives and advantages of this invention will become apparent from the following description taken in conjunction with the accompanying drawings wherein are set forth, by way of illustration and example, certain embodiments of this invention. The drawings constitute a part of this specification and include exemplary embodiments of the present invention and illustrate various objects and features thereof.